Fuel cell stack temperature control

Patent metadata

Field	Value
Publication number	US-2019148749-A1
Application number	US-201715811290-A
Country	US
Kind code	A1
Filing date	Nov 13, 2017
Priority date	Nov 13, 2017
Publication date	May 16, 2019
Grant date	—

Abstract

Various embodiments of the present disclosure provide a fuel cell system configured to modulate the flow of oxidant through the fuel cell system to maintain a desired temperature at the fuel cell stack. The fuel cell system is configured to control the flow of oxidant to maintain the desired temperature in the fuel cell stack based on temperature measurements of fluid outside of the fuel cell stack.

First claim

What is claimed is:

1 . A method of operating a fuel cell system comprising a fuel cell stack comprising multiple fuel cells each comprising an anode and a cathode, the method comprising:
providing, by an oxidant flow control device and at an oxidant mass flow rate, an oxidant to the cathodes; providing, by a fuel flow control device and at a fuel mass flow rate, a fuel to the anodes; controlling, by a controller and based on a current set point, the fuel cell stack to provide an electrical current to an electrical load; sensing, by a temperature sensor, a temperature of the oxidant upstream of the fuel cell stack and sending, by the temperature sensor, a signal representing the sensed temperature to the controller; controlling, by the controller and based on the sensed temperature, the oxidant mass flow rate; controlling, by the controller and based on the current set point, an oxidant heater to heat the oxidant upstream of the fuel cell stack; and determining, by the controller and based on the current set point, the fuel mass flow rate.

2 . The method of claim 1 , further comprising providing, by an auxiliary fuel flow control device and at an auxiliary fuel mass flow rate, an auxiliary fuel to an oxidant heater.

3 . The method of claim 2 , further comprising controlling, by the controller, the oxidant heater to heat the oxidant upstream of the fuel cell stack using the received auxiliary fuel.

4 . The method of claim 3 , wherein controlling the oxidant heater to heat the oxidant point includes determining, by the controller and based on the current set point, the auxiliary fuel mass flow rate.

5 . The method of claim 4 , wherein a first current set point corresponds to a first fuel mass flow rate and a first auxiliary fuel mass flow rate and a second current set point that is greater than the first current set point corresponds to a second fuel mass flow rate that is greater than the first fuel mass flow rate and a second auxiliary fuel mass flow rate that is less than the first auxiliary fuel mass flow rate.

6 . The method of claim 1 , further comprising controlling, by the controller, the oxidant flow control device to provide the oxidant to the cathodes and controlling, by the controller, the fuel flow control device to provide the fuel to the anodes.

7 . The method of claim 1 , further comprising determining, by the controller, a difference between the sensed temperature and a temperature set point.

8 . The method of claim 7 , further comprising controlling, by the controller, the oxidant mass flow rate to reduce the difference between the sensed temperature and the temperature set point.

9 . The method of claim 8 , wherein determining the difference between the sensed temperature and the temperature set point comprises determining, by a proportional-integral-derivative (PID) module of the controller, the difference between the sensed temperature and the temperature set point.

10 . A fuel cell system comprising:
a fuel cell stack comprising multiple fuel cells each comprising an anode and a cathode; an oxidant flow control device in fluid communication with the cathodes and configured to provide an oxidant at an oxidant mass flow rate to the cathodes; a fuel flow control device in fluid communication with the anodes and configured to provide a fuel at a fuel mass flow rate to the anodes; a temperature sensor configured to sense a temperature of the oxidant upstream of the fuel cell stack; an oxidant heater configured to heat the oxidant upstream of the fuel cell stack; and a controller configured to:
control the oxidant flow control device to provide the oxidant to the cathodes;
control the fuel flow control device to provide the fuel to the anodes;
control the fuel cell stack to provide an electrical current to an electrical load based on a current set point;
control the oxidant heater to heat the oxidant upstream of the fuel cell stack based on the current set point;
control the oxidant mass flow rate based on the sensed temperature; and
determine the fuel mass flow rate based on the current set point.

11 . The fuel cell system of claim 10 , further comprising an auxiliary fuel flow control device in fluid communication with the oxidant heater and configured to provide an auxiliary fuel at an auxiliary fuel mass flow rate to the oxidant heater.

12 . The fuel cell system of claim 11 , wherein the oxidant heater is configured to heat the oxidant upstream of the fuel cell stack using the auxiliary fuel received from the auxiliary fuel flow control device.

13 . The fuel cell system of claim 12 , wherein the controller is further configured to control the oxidant heater to heat the oxidant based on the current set point by determining the auxiliary fuel mass flow rate based on the current set point.

14 . The fuel cell system of claim 13 , wherein a first current set point corresponds to a first fuel mass flow rate and a first auxiliary fuel mass flow rate and a second current set point that is greater than the first current set point corresponds to a second fuel mass flow rate that is greater than the first fuel mass flow rate and a second auxiliary fuel mass flow rate that is less than the first auxiliary fuel mass flow rate.

15 . The fuel cell system of claim 10 , wherein the controller is further configured to determine a difference between the sensed temperature and a temperature set point.

16 . The fuel cell system of claim 15 , wherein the controller is further configured to control the oxidant mass flow rate to reduce the difference between the sensed temperature and the temperature set point.

17 . The fuel cell system of claim 16 , wherein a proportional-integral-derivative (PID) module of the controller is configured to determine the difference between the sensed temperature and the temperature set point.

Assignees

• Lg Fuel Cell Systems Inc

Inventors

• Bozzolo Michele
• Caratozzolo Francesco
• Silveira Erel David
• Traverso Alberto

Classifications

• H01M8/04738

  of auxiliary devices, e.g. reformer, compressor, burner · CPC title

• H01M2008/1293

  Fuel cells with solid oxide electrolytes · CPC title

• H01M8/0491

  of fuel cell stacks · CPC title

• H01M8/04335

  of cathode reactants at the inlet or inside the fuel cell · CPC title

• H01M8/04701

  Temperature · CPC title